package cn.tedu.d20_innerclass.work19;

class A{
    public void start(){
        System.out.println("A Start");
    }
}
class B extends A{

    @Override
    public void start(){
        System.out.println("B Start");
    }

    public static void main(String[] args) {
        ((A) new B()).start();//A a=new B();
    }
}